This study is designed to evaluate a potential pharmacokinetic (PK) interaction between indinavir (or ritonavir), zidovudine, lamivudine and an investigational traizole antifungal agent, SCH 56592. This new drug shares a cytochrome p450 metabolic pathway with the protease inhibitors and may interact with zidovudine as does fluconazole (a similar drug) . This study will involve both inpatient and outpatient visits by the subjects. The GCRC staff will aid in patient care and blood drawing. The total duration of the study is 20 days with 3 inpatient days. During the inpatient stays the subjects will receive oral study drugs and PK sampling.